Influence of the Period of Measurements on Wind Potential Assessment for a Given Site

Abstract

The use of wind energy requires knowledge of the wind speed on the site concerned and its temporal variation over a long period, for example, 10 years. But, this requires the control and maintenance of the anemometer to minimize the error on the measurements of wind speed. Moreover, measurements, when they exist on the chosen site, constitute an enormous volume of data, difficult to use in their brut form. Moreover, in general, to install a wind farm, due to the lack of time, we are limited to a short period of measures to assess wind potential, 1 year, for example.

The study of statistical characteristics of hourly average wind speed (HAWS) for the Tangier site, based on 12 years of measurements (1978–1989), was carried out. It has shown that 9 years with four measurements per day (6 h, 9 h, 12 h, and 18 h) is necessary for an adequate study of wind speed, such as histogram, frequencies, and daily, seasonal, and annual variations and for the calculation of K and C parameters of Weibull hybrid distribution, in order to evaluate the wind potential for a given site.

For Tangier case, by limiting the potential assessment to 1 year, the overestimation and underestimation of wind potential can reach 75% for the windiest years and 68% for the least windy for the considered period (1978–1989). From which one may conclude the importance of the measurement step, the number of years, and the reliability of the measurements to study the statistical characteristics of wind speed and, consequently, to assess the wind potential for a given site before installing a wind farm